Stability Aspects of Bulk Carriers

96

PORT SAID UNIVERSITY RESEARCH JOURNAL

Faculty of Engineering- Port Said University

Volume (20) No. 2 September 2016 pp: 96 - 109

Stability Aspects of Bulk Carriers

Nourhan Ibrahim Ghoneim1, El-Sayed Hegazy2, Mohamed A. Kotb3 and Adel A. Tawfik4

ABSTRACT

Bulk carriers are one of the three dominating merchant ship types together with grain and container vessels.

Today, bulk carriers comprise about one third of the world fleet in tonnage terms. The demand for raw materials like

coal, iron, copper, …etc., has increased considerably since the turn of the millennium. Moreover, the bulk carrier has

specific nature due to the loaded bulk cargo’s parameters which may slosh, liquefy, shift...etc.

The intact stability of bulk carriers is investigated, with respect to the latest regulations developed by IMO. The

effect of loading conditions and types of cargoes on ship stability and cargo earning capacity are studied. It is found that

in some cases of loading conditions with certain types of cargo we have to use ballast water to satisfy the new grain

regulations. This will lead to a reduction in the cargo earning capacity of the ship. The study under consideration is very

important from the economic point of view of the vessel’s operation. Ship’s owners and charters must know which type

of bulk cargoes is more profitable in case they have a choice to carry different types of bulk cargoes.

A computer program is developed to carry out the stability calculations. Firstly we should get the vessel’s lines

plans drawings, then using these drawings to prepare the vessel’s tables of offsets. Using these tables of offsets and

Model Maker Program, full model of ship’s sections at different stations and the general arrangement can be obtained.

Take this model in the Auto Hydro program to do the different loading conditions calculations. A programing

code is written and to be run to check the compliance with the intact stability criteria.

Keywords— Bulk carriers- stability- Bulk cargo

Abbreviations and notations:

DWT : Deadweight in (ton)

GMo : The initial metacentric height in (m)

HM : Heeling Moment in (ton.m)

IMO : International Maritime Organization

K : Correction multiplier factor

KG : The vertical vessel’s center of Gravity

(height above the keel) in (m)

R : Angle of Repose in (degree)

MSC : Maritime Safety Committee of IMO

S.F. : Stowage Factor (m3/ t)

SOLAS : Safety Of Life At Sea

SSC : Statical Stability Curve

TSM : Volumetric Transverse Shifting

Moment (m4)

Δ : Displacement in (ton)

ρ : Density in (t /m3)

θ : Heel angle in (degree)

f : Angle of flooding in (degree)

φh : Ship’s angle of heel due to cargo

shifting in (degree)

m : Angle of the maximum difference

between righting arm and heeling

arm in (degrees)

λo : Heeling arm at zero degrees in (m)

λ40 : heeling arm at 40 degrees in (m)

1. INTRODUCTION

1.1 Bulk Carrier’s Definition

The strict technical definition of a bulk carrier has

been adopted by the SOLAS in 1999 [1], and it defines a

bulk carrier as a ship which has a single deck, top side

tanks and hopper side tanks in cargo spaces, as shown in

Figure1, and intended to primarily carry dry cargo in

bulk (e.g. ore, cement, corn, grain, coal….etc.), [2].

1 Egyptian Navigation Company, Alexandria, Egypt. E-mail: [email protected]

2 Faculty of Engineering ,Port Fouad, Port Said University, Egypt. E-mail: [email protected]

3 Faculty of Engineering , Alexandria University, Alexandria, Egypt. E-mail: [email protected]

4 Faculty of Engineering, Port Fouad, Port Said University, Egypt. E-mail: [email protected]

mailto:[email protected]




97

Figure 1: Typical cargo hold structural configuration for a single side skin bulk carrier

1.2 Types of Bulk Carriers

Bulk carriers can be divided on the basis of their

loading/unloading facilities or their cargo carrying

capacity as shown in Table 1:

Table 1: Categories of bulk carrier

On the basis of

the loading/

unloading

facilities:

Geared Carriers This is a ship which has got its own gear (or equipment) to load or unload

cargo. This gear is in the form of cranes or derricks.

Gearless Carriers

Some ships go away with the cranes and derricks but depend on the

equipment available at shore to load/discharge cargo and these are known

as gearless carriers.

On the basis of

the cargo carrying

capacity:

Mini bulk carriers

or MBCs

Are relatively small bulk carriers usually have capacity less than

10,000 DWT.

Handy size carriers

and Handy max

carriers

Are general purpose ships in nature, [3]. These two segments represent

71% of all bulk carriers over 10,000 DWT and also have the highest rate

of growth [4]. Handymax ships are typically 150–200 m in length and

52,000 – 58,000 DWT.

Panamax

carriers

The size of a Panamax vessel is limited by the Panama canal's lock

chambers[5], which can accommodate ships with a beam of up to

33.53 m, a length overall up to 320.04 m, and a depth up to 12.56 m[6].

The capacity of this type is 60,000–99,999 dwt, [7].

Capesize carrier

Capesize ships are too large to traverse the Panama Canal and must round

Cape Horn to travel between the Pacific and Atlantic oceans, a standard

Capesize bulker is around 175,000 DWT, [8].

Very large bulk

carriers

Very large bulk carriers are a subset of the capesize category reserved for

vessels over 200,000 DWT, [9].

2. BULK CARRIER’S STABILITY

Solid bulk cargoes are usually loaded by pouring

directly into a ship’s cargo holds. If a solid bulk cargo is

poured onto one spot, it naturally forms a conical pile

with distinctive slope angle, called the Angle of Repose

‘R’[10].

This is determined by the friction between the

individual particles of the stow, which, in turn, depends

upon the cargo commodity, its moisture content and the

size and shape of the individual particles; see Figure2

and Table 2.

Figure 2: Angle of Repose for a solid bulk cargo [11]

Angle of Repose (R) R R

http://en.wikipedia.org/wiki/Deadweight_tonnage

98

If a particularly heavy roll heels a vessel beyond

the cargo’s angle of repose, then the stow becomes

unstable, as in condition 3, as shown in Figure 3. If the

shift of cargo occurs, then the ship will roll about an

angle of list so the return roll is unlikely to restore the

cargo to the level state. Further rolling will produce even

greater angles of heel towards the side of shifted cargo.

This, in turn, can lead to further shifts of the stow which

causes the list to progressively increase. The process will

either capsize the ship or reach a stable listed state,

depending upon the vessel’s transverse stability

characteristics.

Figure 3: Behavior of a trimmed bulk cargo with angles of heel “θ”

Table 2: Examples of the angle of repose (R) and stowage factor (S.F.) of some different solid bulk cargoes

in m3/t [12]

Solid Bulk Cargoes S. F. (m3/t) Angle of Repose

Ammonium Nitrate UN 1942 1 27°to 42°

Ammonium Sulphate 0.95 to 1.06 28° to 35°

Monoammonium Phosphate 1.0 to 1.21 35° to 40°

Potash 0.77 to 1.03 32° to 35°

Potassium Chloride 0.81 to 1.12 30° to 47°

Superphosphate 0.81 to 1.00 30° to 40°

3. FORMULATION of BULK CARRIER STABILITY PROBLEM

The angle of the heel due to solid bulk cargo shift

(h) can be determined. Any bulk carrier, must have data,

regarding the hold spaces, so that the KG and volumetric

heeling moment for each stow can be calculated. TSM

called simply the Moment of Water plane Inertia or,

more correctly, the Second Moment of Area and this

moment indicates the rate at which the underwater hull

shape changes with angle of heel and it is an important

factor in determining the hull form's resistance to rolling

[13]. It is the moment caused by the shift in the Centre of

Buoyancy per radian of water plane area rotation. This

information is supplied by the shipbuilder in the form of

tables or diagrams, for each cargo space, as shown in

Figure4. Figure4 shows typical variations of volumetric

heeling moment (curve No.1), stow’s height of VCG

from the keel (curve No.2) and volumetric capacity

( c u r v e N o . 3 ) w i t h h o l d u l l a g e .

The fluid KG of loaded vessel in the upright

condition is calculated in the normal way by taking

moments of individual weights about the keel and

allowing for free surface effects of any slack tanks.

Heights of cargo stows in the holds are obtained by

measuring their ullages (i.e. the depths of the stow’s top

surface from the hatch top). The ullage values are used

to obtain the KG, volume and volumetric heeling

moment of each grain stow. The weight of each stow is

calculated as follows:

99

Weight of cargo stow (ton) = Volume of

stow/Stowage factor (1)

The value of the stowage factor, S.F. is generally

used instead of bulk density, ‘ρ’ and should be supplied

by the grain shipper, prior to loading.

S.F. = 1/ ρ (m3/t) (2)

Values of KG and volumetric heeling moments

must be corrected for all partially filled holds with the

appropriate factors of ‘K’, as shown below, before being

used in the KG calculation.

The calculations’ steps of the angle of heel due to

solid bulk cargo shift (h) are as follows:

a. Find out the Volumetric Transverse Shifting

Moment (TSM) in (m4) for each cargo hold

corresponding to the loaded cargo’s volume (m3)

from the vessel’s tables.

b. In order to take into account the adverse effect of

vertical shift of grain/bulk cargoes surfaces in

"partially filled compartment", Volumetric

Transverse Shifting Moment has to be multiplied

by "K" where multiplier "K" is given by; according

to [14];

1.06 For "fully filled compartments".

1.12 For "partly filled compartment".

Stow

's h

eigh

t of

VC

G fro

m the

kee

l (m

)

Vol

umet

ric ca

pacity

(m3)

Volumetric heeling moment (m4)

Figure 4: Grain Characteristics for a hold [11]

c. Transform Volumetric Transverse Heeling Moment

(TSM) in (m4) into Heeling Moment (HM) (t.m)

from the following formula, [14]:

HM = K. TSM (m4)/ S.F. (m3/t) in (t.m) (3)

d. Find the value of heeling arm (λo) at zero and the

value of heeling arm (λ40) at 40 degrees,

respectively, by the formulae, [15]:

tonntDisplaceme

mtMomentHeelingTotal .0 (4)

And

040 *8.0 (5)

Draw the heeling arm curve due to transverse grain

shift which may be approximately represented by the

straight line A-B where A and B are the ordinates. Find

the intersection point between this curve and the righting

arm curve. This point represents the angle of heel due to

shift of grain (h), see Figure 5.

Figure 5: Determination of the angle of the heel due to solid bulk cargo shift (h)

GZ (m)

100

4. THE STABILITY CRITERIA REQUIRED BY THE GRAIN REGULATIONS, [16]

The intact stability criteria as per the Grain

Regulations A.749 (18), [17], Maritime Safety

Committee MSC.23(59), [18] and Chapter VI, SOLAS

1974, [19] according to the intact stability characteristics

of any ship carrying bulk cargoes should meet,

throughout the voyage, at least the following criteria

after taking into account the heeling moments due to dry

bulk cargo shift:

i. In the statical stability flow chart, see Figure 5, the net

residual area between the heeling arm curve due to

transverse grain shift and the righting arm curve up to

the angle of heel of maximum difference between the

ordinates of the two curves, (m), or 40 degrees or the

“angle of flooding“, (f), whichever is the least, shall in

all conditions not be less than 0.075 meter-radians; i.e,

Residual Dynamical Stability ≥ 0.075 (meter-

radians) (i)

ii. The angle of heel due to shift of grain, h, shall not be

greater than 12 degrees i.e,

h ≤ 12o (ii)

iii. The initial metacentric height, after correction for the

free surface effects of liquids in tanks, shall not be less

than 0.3 meters, i.e,

GMo ≥0.3 m (iii)

5. APPLICATION OF PROPOSED PROCEDURE

In what follows an illustrative example given to

show the procedure to be followed to investigate the

stability problem of bulk carriers at different conditions

of loading with different types of bulk cargo.

5.1 Bulk Carrier’s Specifications Table 3 summarizes the candidate vessel’s principal

particulars.

Table 3: Vessel Principal Particulars M/V “Gold Stone”

Length Over All (LOA) 91.0 m

Length between Perpendiculars (LBP) 83.0 m

Breadth (B) 15.0 m

Depth to main Deck (D) 7.3 m

Summer Draft (T) 6.0 m

Light Ship Weight 1674.57 ton

Gross Tonnage 2827

Net Tonnage 1822

Engine Type 6320 ZCD-6

Engine Power 1545 K.W

Frame spacing 600 mm

Longitudinal Center of gravity (LCG) -5.313 m (fore)

Vertical center of gravity (KG) 5.70 m

Number of cargo holds 2

Year of Built 2007

5.2 Stability Calculations Flow Chart

A computer program is developed to carry out the

stability calculations. The following flow chart, see

Figure 6, explains the steps to meet the above mentioned

criteria.

Table of offsets was developed and from these

tables a model for the vessel was developed using Model

Maker software. This model was used to carry out some

loading conditions for the candidate vessel using

AutoHydro software. Then the stability criteria for every

loading condition were checked and analyzed as follows

in the next sections of this paper.

5.3 Loading Conditions

Stability calculations are carried out at the

following loading conditions:

a) Full load departure condition:

The ship is fully loaded with cargo homogenously

distributed through all cargo holds and with full stores

and consumables, [20].

In this case:

Ship’s displacement (Δ) = 6164.563 Ton Cargo weight = 4184.283 Ton

Draft = 6 m

No ballast water onboard

b) Half load (50%) departure condition:

In this case:

Ship’s displacement (Δ) = 4072.4215 Ton

Cargo weight = 2092.1415 Ton

Draft = 6 m


c) 25% load departure condition:

In this case:

101

Ship’s displacement (Δ) = 3026.351 Ton

Cargo weight = 1046.0708 Ton

Draft = 6 m


Figure 6: Stability diagram flow chart

5.4 Different Types of Bulk Cargo

The types of bulk cargo are represented by what

so called stowage factor (S.F.) in (m3/ton).

Bulk carriers usually designed to carry different

types of bulk cargo with different stowage factors as

given in Table 2.

This means that a bulk carrier must meet the

stability grain regulations at all types of bulk cargo for

which the ship is designed to carry. In this study the

stability calculations for the vessel under consideration

were carried out at different stowage factors, namely,

1.5, 1.25, 1.0, 0.8, and S.F. 0.667 m3/t, to study the

effect of the type of cargo on ship’s stability for

different loading condition (full load, half load,….etc.).

6. RESULTS and DISCUSSION of THE PROCEDURE

Figure 7 shows GZ – curve for full load departure

with cargo onboard of 1.25 m3/t stowage factor while

Table 4 gives the stability checkup for the same

loading condition as an example of the obtained results

for different loading conditions mentioned above.

Figure 8 shows GZ – curves for full load

departure with different types of cargo (i.e. different

values of S.F.). Also these results are given in Table 5.

It is clear from the figure that there are two areas,

one of them is stable area where all stability criteria are

satisfied (for S.F. ≥ 1.25 m3/t), while the second area is

unstable (for S.F. ≤ 1.0 m3/t).

This means that the vessel under consideration is

designed to carry light bulk cargo with S.F. ≥ 1.25 m3/t.

In order that this vessel can carry safely heavy

bulk cargo with S.F. ≤ 1 m3/t, it must have onboard

certain quantity of ballast water in certain ballast tanks

Start

Stability and trim calculation

GMo ≥ 0.3 m

Actual heeling moment calculation

Yes

Calculation of heeling angle and residual dynamical

stability

Angle of Heel ≤ 12o

No

No

Residual Area ≥ 0.075 m.rad.

No

Yes

Yes

End

An

oth

er lo

adin

g co

nd

itio

n s

ho

uld

be

con

sid

ered

102

located in the double bottom and this will reduce the cargo earning capacity of the ship.

Figure 7: statically stability curve (SSC) for full load departure (S.F. 1.25 m3/ton) as an output of the

Autohydro software

Table 4: Stability checkup for full load departure (S.F. 1.25 m3/ton) as an output of the Autohydro software

Min/Max Actual Margin Pass

(1) Area from 0 deg. to 30 ≥ 0.055 m-R 0.107 0.052 Yes

(2) Area from 0 deg. to 40or Flood ≥ 0.09 m-R 0.152 0.062 Yes

(3) Area from 30 deg. to 40 or Flood ≥ 0.03 m-R 0.045 0.015 Yes

(4) Righting Arm at 30 deg. ≥ 0.2 m 0.282 0.082 Yes

(5) Absolute Angle at Max. R.A. ≥ 25 deg. 27.31 2.31 Yes

(6) GM at Equilibrium ≥ 0.15 m 0.903 0.753 Yes

(7) Area from 0 deg. to 40 or Flood ≥ 0.075 m-R 0.152 0.077 Yes

(8) GM at Equilibrium ≥ 0.3 m 0.903 0.603 Yes

This was done and the results are shown on Figure

9. It was found that in the case of S.F. equals to 0.8 m3/t,

we have to carry an amount of 535.2 tons of water as a

ballast to satisfy all stability criteria (see Table 5 and

Table 6). As a result of ballasting operation the quantity

of cargo to be carried onboard is reduced from 4184.283

tons to 3649.083 tons i.e. cargo earning capacity is

reduced by 12.79%.

For other loading conditions (i.e. 50% and 25%) the

results are shown on figure 10 (and table 7) and figure

11 (and table 8), respectively. It is clear that for these

load conditions the vessel meet all grain stability criteria

when loaded with different cargoes without need to carry

ballast onboard.

It should be noted that one can say that for the same

vessel and for the same loading condition, when the S.F.

value increases (i.e. light cargo) the value of KG

increases. In fact, in our case study, this is not usually

true for all cases, since the cargo distribution in cargo

holds as well as water ballast is not the same in all cases

of loading conditions.

7. CONCLUSIONS

Bulk carriers comprise about one third of the world

fleet in tonnage terms. Due to the nature of the bulk

cargoes, bulk carriers face some stability problems.

For safe operation of such vessels IMO developed

special stability criteria, which must be satisfied.

This paper gives a brief discussion of such

regulations and a computer program was developed to

carry out stability calculations for such vessels.

The effects of loading conditions as well as the

type of bulk cargo carried onboard were examined. It

was found that in some cases of loading conditions with

-0.15

-0.1

-0.05

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0 10 20 30 40 50 60 70

λ40λ0

φh

θ Heeling Angle (in deg.)

Residual Dynamical Stability

Rig

hti

ng

Arm

(G

Z)

(in

m)

Max. GZ

GMo

103

certain type of cargo we have to use ballast water to

satisfy the new grain regulations. This will lead to a

reduction in the cargo earning capacity of the ship. The

study under consideration is very important from the

economic point of view of the vessel’s operation. Ship’s

owners and charters must know which types of bulk

cargoes are more profitable in case they have a choice to

carry different types of bulk cargoes.

Figure 8: Righting Arm Curves (GZ Curve) in the Full Load Condition

Figure 9: Righting Arm Curves (GZ Curve) in the Full Load Condition

-0.3

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0 10 20 30 40 50 60 70

Rig

hti

ng

Arm

(m

)

Heel Angle (deg)

Stable Area

unstable Area

Δ = 6164.563 t

-0.2

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

0 10 20 30 40 50 60 70

Rig

hti

ng

Arm

(m

)

Heel Angle (deg)

Stable Area

Δ = 6164.563 t

104

Figure 10: Righting Arm Curves (GZ Curve) in the Half Load (50%) Departure Condition

Figure 11: Righting Arm Curve (GZ Curve) in 25% Loading Departure Conditions

-0.4

-0.2

0

0.2

0.4

0.6

0.8

0 10 20 30 40 50 60 70Rig

hti

ng

Arm

(m

)

Heel Angle (deg)

S.F.1.5

S.F. 1.25

S.F. 1

S.F. 0.8

S.F. 0.667

Δ = 4072.4215 t

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

0 10 20 30 40 50 60 70 80

Rig

hti

ng

Arm

(m

)

Heel Angle (deg)

S.F.1.5

S.F. 1.25

S.F. 1

S.F. 0.8

S.F. 0.667

Δ = 3026.351 t

105

Table 5: Stability criteria for candidate ship in full load departure when loaded with bulk cargoes with different S.F.

Loading condition Full load departure (condition No.1)

Item

Stowage factor S.F. = 0.667 S.F. = 0.8 S.F. = 1 S.F. = 1.25 S.F. = 1.5

Summer draft (m) 6

Light ship weight (ton) 1,674.57

Fixed weight (ton) 3.5

Cargo in Hold (1) (ton) 1683.4 697.056 1,301.26 1840.212 1531.905

Cargo in Hold (2) (ton) 2500.883 3487.227 2,880.56 2281.455 1899.084

Consumables (ton) 302.21

Deadweight (ton) 4489.99

Ballast onboard (ton) 70 No ballast No ballast 62.616 753.2

Displacement (ton) 6164.563

VCG (KG) (m) 4.861 3.972 4.868 5.197 4.799

Stability criteria Actual Pass Actual Pass Actual Pass Actual Pass Actual Pass

(1) Area from 0 deg. to 30 ≥ 0.055 m-R 0.041 No 0.050 No 0.104 Yes 0.107 Yes 0.145 Yes

(2) Area from 0 deg. to 40 or Flood ≥ 0.09 m-R 0.013 No 0.063 No 0.135 Yes 0.152 Yes 0.220 Yes

(3) Area from 30 deg. to 40 or Flood ≥ 0.03 m-R -0.028 No 0.014 No 0.030 No 0.045 Yes 0.075 Yes

(4) Righting Arm at 30 deg. ≥ 0.2 m -0.035 No 0.107 No 0.242 Yes 0.282 Yes 0.417 Yes

(5) Absolute Angle at MaxRA ≥ 25 deg 16.92 No 22.62 No 23.82 No 27.31 Yes 40.21 Yes

(6) GM at Equilibrium ≥ 0.15m 0.725 Yes 0.579 Yes 1.217 Yes 0.903 Yes 1.076 Yes

(7) Area from 0 deg to 40 or Flood ≥ 0.075 m-R 0.013 No 0.063 No 0.135 Yes 0.152 Yes 0.220 Yes

(8) GM at Equilibrium ≥ 0.3 m 0.725 Yes 0.579 Yes 1.217 Yes 0.903 Yes 1.076 Yes

(9) The angle of heel due to cargo shift, h ≤ 12o 7.7 Yes 4.6 Yes 3.6 Yes 2.1 Yes 2 Yes

106

Table 6: Stability criteria for candidate ship in full load departure when loaded with bulk cargoes with different S.F.

Loading condition Full load departure (condition No.1 with ballast water added)

Item

Stowage factor S.F. = 0.8 S.F. = 1 S.F. = 1.25 S.F. = 1.5

Summer draft (m) 6



Cargo in Hold (1) (ton) 697.056 1335.658 1840.212 1531.905

Cargo in Hold (2) (ton) 2952.027 2565.23 2281.455 1899.084



Ballast onboard (ton) 535.2 283.4 62.616 753.2


VCG (KG) (m) 4.259 4.888 5.197 4.799

Stability criteria Actual Pass Actual Pass Actual Pass Actual Pass

(1) Area from 0 deg. to 30 ≥ 0.055 m-R 0.083 Yes 0.099 Yes 0.107 Yes 0.145 Yes

(2) Area from 0 deg. to 40 or Flood ≥ 0.09 m-R 0.119 Yes 0.133 Yes 0.152 Yes 0.220 Yes

(3) Area from 30 deg. to 40 or Flood ≥ 0.03 m-R 0.036 Yes 0.034 Yes 0.045 Yes 0.075 Yes

(4) Righting Arm at 30 deg. ≥ 0.2 m 0.222 Yes 0.248 Yes 0.282 Yes 0.417 Yes

(5) Absolute Angle at MaxRA ≥ 25 deg 28.61 Yes 26.27 Yes 27.31 Yes 40.21 Yes

(6) GM at Equilibrium ≥ 0.15m 1.030 Yes 1.060 Yes 0.903 Yes 1.076 Yes

(7) Area from 0 deg to 40 or Flood ≥ 0.075 m-R 0.119 Yes 0.133 Yes 0.152 Yes 0.220 Yes

(8) GM at Equilibrium ≥ 0.3 m 1.030 Yes 1.060 Yes 0.903 Yes 1.076 Yes

(9) The angle of heel due to cargo shift, h ≤ 12o 3.1 Yes 2.8 Yes 2.1 Yes 2 Yes

107

Table 7: Stability criteria for candidate ship in half load departure when loaded with bulk cargoes with different S.F.

Loading condition Half load departure (condition No.3)

Item


Summer draft (m) 6



Cargo in Hold (1) (ton) 2092.142 2092.142 1161.505 929.4 774.55

Cargo in Hold (2) (ton) 0 0 930.6365 1162.742 1317.592



Ballast onboard (ton) No ballast No ballast No ballast No ballast No ballast



(1) Area from 0 deg. to 30 ≥ 0.055 m-R 0.136 Yes 0.145 Yes 0.117 Yes 0.169 Yes 0.197 Yes

(2) Area from 0 deg. to 40 or Flood ≥ 0.09 m-R 0.203 Yes 0.231 Yes 0.186 Yes 0.264 Yes 0.314 Yes


(4) Righting Arm at 30 deg. ≥ 0.2 m 0.463 Yes 0.526 Yes 0.436 Yes 0.592 Yes 0.686 Yes

(5) Absolute Angle at MaxRA ≥25 deg 30.20 Yes 32.74 Yes 33.55 Yes 31.93 Yes 33.83 Yes

(6) GM at Equilibrium > 0.15m 0.813 Yes 0.908 Yes 0.610 Yes 1.078 Yes 1.362 Yes

(7) Area from 0 deg to 40 or Flood ≥ 0.075 m-R 0.203 Yes 0.231 Yes 0.186 Yes 0.264 Yes 0.314 Yes


108

Table 8: Stability criteria for candidate ship in 25% load arrival when loaded with bulk cargoes with different S.F.

Loading condition 25% load arrival (condition No.5)

Item


Summer draft (m) 6



Cargo in Hold (1) (ton) 1046.071 1046.071 696.903 557.64 774.55

Cargo in Hold (2) (ton) 0 0 349.1678 488.4308 271.5208



Ballast onboard (ton) No ballast No ballast No ballast No ballast No ballast



(1) Area from 0 deg. to 30 ≥ 0.055 m-R 0.168 Yes 0.197 Yes 0.181 Yes 0.173 Yes 0.209 Yes



(4) Righting Arm at 30 deg. ≥ 0.2 m 0.660 Yes 0.726 Yes 0.663 Yes 0.672 Yes 0.793 Yes

(5) Absolute Angle at MaxRA ≥25 deg 36.72 Yes 35.19 Yes 39.37 Yes 39.37 Yes 34.40 Yes

(6) GM at Equilibrium > 0.15m 0.994 Yes 1.208 Yes 0.696 Yes 1.037 Yes 1.065 Yes

(7) Area from 0 deg to 40 or Flood ≥ 0.075 m-R 0.284 Yes 0.322 Yes 0.295 Yes 0.295 Yes 0.344 Yes


109

8. REFERENCES:

[1]http://www.brighthub.com/engineering/marine/articl

es/11736.aspx, last updated 7/12/2009.

[2] SOLAS - International Convention for the Safety of

Life at Sea - Articles of the International Convention

for the Safety of Life at Sea, 1974.

[3] http://en.wikipedia.org/wiki/Handysize, last

updated January 2010.

[4] http://en.wikipedia.org/wiki/Handymax, last

updated 12/11/2010.

[5] Autoridad Del Canal de Panamá 2005, pp.11 – 12,

http://en.wikipedia.org/wiki/Panamax, 25 July 2013.

[6] http://maritimeconnector.com/wiki/panamax.

[7] United Nations Conference on trade and

development UNCTAD, Review of Maritime

Transport 2014, UNCTAD/RMT/2014 UNITED

NATIONS publication, 2014.

[8] Reuters Africa, Thomson Reuters (af.reuters.com),

26 July 2010. http://en.wikipedia.org/wiki/Capesize,

"Egypt's Suez Canal H1 revenue, traffic up; upgrade

helps". Retrieved 26 March 2011.

[9] MAN Diesel Group, p.3-4, http://maritime-

connector.com/wiki/vlcc/, 2005.

[10] Edward V. Lewis, Principles of Naval

Architecture VOL I, stability and strength, Editor,

Published by the society of naval architects and marine

engineers, 601 Pavonia Avenue, Jersey City, NJ, 1988.

[11] BC 2004 Code - Code of Safe Practice for Solid

Bulk Cargoes, 2004 Resolution MSC.193(79) - Section

1 – Definitions, 2004.

[12] Resolution MSC.268 (85) – Adoption of the

International Maritime Solid Bulk Cargoes (IMSBC)

Code – The Maritime Safety Committee, Adopted 4

December 2008.

[13] K.J. Rawson and E.C. Tupper, Basic Ship Theory,

5th ed.,volume 2, Published by the Longman Group

Ltd., 2001.

[14] David G.M. Watson, Practical ship design,

Published by the Elsevier Science Ltd., The Boulevard,

Oxford, UK 1998.

[15] Ian. C. Clark, The Management of merchant Ship

Stability, Trim and Strength, first published 2002 by

The Nautical Institute, London, England, 2002.

[16] The International Maritime Organization (I.M.O.)

'Code of Intact Stability', 1995.

[17] IMO Resolution A.749(18) - Code on Intact

Stability for all Types of Ships Covered by IMO

Instruments , adopted on 4 November 1993.

[18] Resolution MSC.23(59) - Adoption of the

International Code for the Safe Carriage of Grain in

Bulk, adopted on 23 May 1991.

[19] SOLAS - International Convention for the Safety

of Life at Sea - Articles of the International Convention

for the Safety of Life at Sea, Chapter VI - Carriage of

cargoes and oil fuels, SOLAS 1974.

[20] Intact Stability (IS) Code - Intact Stability for All

Types of Ships Covered by IMO Instruments,

Resolution A.749(18), Amended by MSC.75(69),

Adopted on 14 May 1998.

http://www.brighthub.com/engineering/marine/articles/11736.aspx

http://www.brighthub.com/engineering/marine/articles/11736.aspx

http://en.wikipedia.org/wiki/Handysize

http://en.wikipedia.org/wiki/Handymax

http://en.wikipedia.org/wiki/Panamax

http://en.wikipedia.org/wiki/Capesize

http://af.reuters.com/article/idAFJOE66P09P20100726

http://af.reuters.com/article/idAFJOE66P09P20100726

http://maritime-connector.com/wiki/vlcc/

http://maritime-connector.com/wiki/vlcc/

mk:@MSITStore:C:/Program%20Files/Lloyd's%20Register/Rulefinder/9.15/Rulefinder_STAT.chm::/imodoc350.html

Documents

Stability Aspects of Bulk Carriers